Recently, high-temperature rapid development of photographic materials has been popularized noticeably, and the processing time has been greatly reduced by using various kinds of automatic processors. In order to satisfactorily attain rapid processing of photographic materials, developers are required which are capable of providing sufficient sensitivity to the processed materials in a short processing time. In addition, photographic materials having a high rate of development to provide sufficient density in a short processing time and having a short drying time after rinsing are required.
A method which is generally employed in order to improve the drying property of photographic materials includes a method of first adding a sufficient amount of a hardening agent (gelatin-crosslinking agent) to the photographic material during coating in order to reduce the swelling rate of the emulsion layers and the hydrophilic colloid layers during development, fixation and rinsing, whereby the water content of the processed materials before initiation of drying is reduced. In accordance with this method, the drying time may be reduced depending upon the use of a larger amount of the hardening agent added to the photographic materials.
However, the addition of a larger amount of the hardening agent to the photographic materials causes a reduction in the swelling rate of the layers, whereby the rate of development, the sensitivity, the contrast and the covering power are lowered. Even if the rate of development of the photographic materials could be improved by this method, the rate of fixation is lowered as the photographic materials are greatly hardened, which causes various problems, such as an increase in residual silver, an increase in residual hyposulfite (hereinafter "hypo") and an increase in coloration of the processed materials due to the remaining sensitizing dyes therein. These problems have heretofore been a bar to a reduction of the processing time of photographic materials.
On the other hand, a method of elevating the developing activity of developers is known, in which the amount of the developing agent and/or the amount of the auxiliary developing agent are/is increased, the pH value of the developer is elevated, or the processing temperature is elevated. However, this method involves various drawbacks, for example, the preservability of the developers is lowered, the contrast of the processed materials is lowered and/or the processed materials are fogged even though the sensitivity is elevated.
In order to improve the above-mentioned problems, the technology of employing tabular grains has been proposed, for example, as described in U.S. Pat. Nos. 4,439,520 and 4,425,425. Also, JP-A 63-305343 and JP-A 1-77047 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") disclose technology of elevating the rate of development and the ratio of sensitivity/fog by controlling the development starting point of silver halide grains having a (111) plane to the corners and/or edges and their environs of the grains. JP-A 58-111933 disclose a photographic element for radiography having an elevated covering power due to a restriction of the swelling ratio of the hydrophilic colloid layer containing tabular grains to be 200% or less, and the addition of a hardening agent to the element during processing is unnecessary. These known methods are valuable for improving the rate of development of photographic materials. However, reduction of the processing time for photographic materials with respect to developing, fixing and rinsing causes various problems, such as a decrease in photographic sensitivity and also an increase of residual silver and residual hypo. These problems can generally be attributed to a worsening in the fixation of the processed materials.
If the materials are color-sensitized with sensitizing dyes, another problem in present, that is, coloration of the processed materials due to the dyes which remain therein (residual color).
Improving photographic properties of photographic materials only by modifying the silver halide grains is naturally limitative and, after all, is based on the film property of the materials. Specifically, fixation of processed photographic material as well as residual color depends upon the thickness of the hydrophilic colloid layers constituting the material, which bars elevation of the rapid processability of the photographic materials.
In this connection, JP-A 64-73333, 64-86133, 1-105244, 1-158435 and 1-158436 disclose a means of controlling the amount of gelatin in the hydrophilic colloid layers containing silver halide emulsion layers within the range of from 2.00 to 3.50 g/m.sup.2 and combining other techniques to attain ultra-rapid processability of photographic materials capable of being processed in a total processing time of from 20 seconds to less than 60 seconds. JP-A 2-68537 discloses a means of controlling the weight ratio of silver in the light-sensitive silver halide to gelatin (silver/gelatin) in the coated emulsion layer to 1.5 or more to attain ultra-rapid processability of photographic materials. JP-A 63-221341 discloses a means of preparing a photographic material by coating an emulsion layer consisting essentially of tabular silver halide grains having an aspect ratio of grain diameter to grain thickness of being 5 or more, the material having a gelatin content of from 2.00 to 3.20 g/m.sup.2 and having a melting time of from 8 seconds to 45 seconds; and the material thus prepared may be processed by ultra-rapid processing with a total processing time of from 20 seconds to less than 60 seconds.
Investigating the known methods, the present inventors have found that when the gelatin content is reduced or when the ratio of silver/gelatin is elevated while the silver content is kept constant, the materials have noticeably increased scratch marks or roller marks. Scratch marks are black streaks formed on processed photographic materials due to the rubbing of films with each other or the rubbing of a film with any other substance during the handling of films. Roller marks are black spots formed on processed photographic material due to pressure of small hills or hollows of the surface of the conveying roller applied to photographic materials during processing in an automatic processor. Thus, the materials are at a practically unacceptable level. As a result, photographic products applicable to ultra-rapid processing could not be completed.
Where the total processing time of known photographic materials was 60 seconds or less, especially 40 seconds or less, with suitably apportioning of the time among the development, fixation and rinsing steps, the materials often involved problems in drying if the environment of the automatic processor had a high humidity and if the gelatin content of the materials was not 2.5 g/m.sup.2 or less. However, such reduction of the gelatin content in photographic materials is unacceptable from the viewpoint of the chance for an increase of roller marks and scratch marks in the processed photographic materials.
A mentioned above, the drying property, pressure resistance and fixability (i.e., elimination of residual color due to sensitizing dyes) of photographic materials could not satisfactorily be improved merely by controlling the gelatin content.
It is well known to incorporate polymers having --COOH or its salt structure into photographic materials or to incorporate the polymers along with a hydrophilic colloid of gelatin thereinto.
For instance, JP-B 57-53587 and 57-15375 (the term "JP-B" as used herein means an "examined Japanese patent publication"), German Patent 1,745,061, JP-B 49-23827, 55-14415 and 55-15267, JP-A 48-89979, U.S. Pat. Nos. 2,279,410 and 3,791,831 and JP-B 47-28937 disclose incorporating a carboxyl group-containing polymer into a photographic material to prevent static charging of the material. However, these documents do not disclose controlling the swelling rate of the hydrophilic colloid layer of the material to promote the drying rate of the material due to incorporation of an anionic high polymer antistatic agent. In general, a large amount of an anionic antistatic agent is often incorporated into a specific hydrophilic colloid layer and a large amount of a gelatin hardening agent is often incorporated into a photographic material so as to improve the physical properties of the film. If such an anionic antistatic agent is utilized for controlling the swelling property of a processed photographic material so as to reduce the drying load of the material, as sought in the present invention, problems such as an increase of residual silver and residual hypo occur, as in the above-mentioned invention of JP-A 58-111933.
European Patent Nos. 75231 and 167081, JP-A 53-7231, 60-126644, 60-156056, 2-20861, JP-B 1-14574 and U.S. Pat. No. 4,142,894 disclose employing a carboxyl group-containing high polymer mat agent. However, a mat agent naturally results in grains having a grain size of approximately from 0.2 to 10 .mu.m on the surface of a photographic material. When exposed to light, the agent displays its function due to the surface roughness of the material. Such coarse and large grains are not sufficient for attaining the function of controlling the swelling rate of processed photographic material, as sought by the present invention.
JP-A-2-207242 discloses incorporating a polyacrylic acid derivative into a photographic material having an anti-halation layer containing an ammonium structure-containing a high polymer mordant agent and an anionic dye so as to improve the decolorability of the anionic dye. However, there is no disclosure of controlling the swelling rate of the processed photographic material due to a --COOH group-containing polymer. In fact, the present inventors have clarified that acrylic acid homopolymers as described in JP-A-2-207242 have no effect on improving the drying property of photographic materials containing them based on the swelling rate controlling effect of photographic materials processed substantially in the absence of a hardening agent.
Polymers containing a repeating unit of an acid component which is water-insoluble at a pH&lt;6 and is water-soluble at a pH&gt;10, are disclosed. For example, German Patent 3,608,744 describes emulsion polymers of copolymer couplers. However, since polymers of this kind are substantially insoluble in water and alkali substances, they do not function to control the swelling rate of processed photographic materials like those mentioned above.